• The Journal of the Petrological Society of Korea
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• v.16 no.4
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• pp.217-232
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• 2007

The Puu Oo eruption in Hawaii since 1983 is one of the largest eruptions on Hawaii's volcanic history with prominent compositional variation ($5.6{\sim}10.1wt.%$ in MgO content). Although intense researches of Hawaiian eruption have been conducted for recent years, there is no up-to-date study on Puu Oo lavas that is erupting hot lavas today. in oder to obtain basic information on the geological characteristics of the eruption including any noticeable change in its petrological trend and magma dynamics, we applied several geological approaches such as field survey, systematic sampling, petrography, mineralogy, and geochemistry. Clinopyroxene and Plagioclase phenocrysts are rarely observed on the thin section, however Olivine crysts are much more obvious in the study area. It indicates that Puu Oo is early stage of magma differentiation. Variation diagram of whole rock composition shows that the elements such as $TiO_2,\;Al_2O_3,\;SiO_2$ and $Na_2O$ decrease with increasing MgO. In the trace element Sr, Y Zr and V versus $K_2O$, P18, P19 samples are plotted in primitive area. Variations of the Ni contents during $2003{\sim}2006$ may suggest a sudden change in magma composition probably caused by new magma injection.

• The Journal of the Petrological Society of Korea
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• v.12 no.4
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• pp.184-195
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• 2003

Hawaii Island makes up of five volcanos of Kohala, Mauna Kea, Hualalai, Mauna Loa, and Kilauea. They are big shield volcanoes rising above the Pacific ocean floor and final two volcanoes provide a natural laboratory for the study of active volcanoes. Mauna Loa is the largest single volcano on earth. At the submmit is an oval-shaped Mokuaweoweo caldera, from which two rift zones extend to the southwest and northeast, and in the medial part are the longest lava tube systems in the world. Kilauea has been formed largely by eruption along southwest and eastern rift zones extending from Kilauea caldera at the submmit. On the eastern rift zone, spectacularly, the 1989-1974 eruption of Kilauea at Mauna Ulu crater formed the Mauna Ulu lava flow field. The 1983-1986 eruption of aa flows at Puu Oo crater, and the activities of pahoehoe flows during 1986-1990 at Kupaianaha crater and during 1991-recent at the Puu Oo has produced the Puu Oo and Kupaianaha lava flow field.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.675-689
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• 2007

Kilauea volcano's summit area was formed by continuous ind/or sporadic eruption activities for several hundreds years. In this study, we mainly focused on the trace elements characteristics through systematic sample rocks erupted from 1790 to September of 1982. Under the microscope it can be observed some main minerals such as olivine, clinopyroxene. and plagioclase with minor opaque minerals including Cr-spinel and ilmenite. Zr, V, Y, Ti elements show incompatible activities with MgO while Ni, Cr, Co elements show highly compatible properties. Elements like as Ba, Rb, Th, Sr, Nd are highly incompatible to show positive trends with $K_2O$. In the REE diagram LREE is more enriched than HREE suggesting typical Oceanic Island Basalt(OIB) type. It can be suggested that Sr have an effect on the fractionation of plagioclase from the kink in the $K_2O$ variation diagram. Y/Ho ratio diagram shows there was no fluids effect in the historical Kilauea volcano but Zr/Hf ratio diagram shows a significant difference between Kilauea lavas and PuuOo lavas. There are distinctive changes of trace element contents showing in particular abrupt changes of temporal variations between 1924 and 1954. Moreover, PuuOo lavas which had been erupted since 1983 follow these decreasing trends of trace element variation. Therefore, it is strongly suggested that these abrupt changes of trace elements trends result from the huge collapse geological event which formed Halemaumau crater in 1924 causing contamination effects of crustal contents into magma chamber and from the changes of parental magma composition injected into Kilauea volcano's summit magma reservoir.